This invention relates to the production of glass fibers and glass fiber products. More particularly the invention relates to high speed glass fiber attenuators.
Glass fibers are formed by attenuating molten cones of glass at tips of orifices in a fiber forming bushing. The attenuating forces are supplied by the engagement of the filaments with the exterior of a sleeve received by a rotary spindle and the strand is wound on the sleeve as a forming package.
Another means of applying attenuating forces to the fibers is by pulling the strand between two continuous surfaces traveling at high speeds such as is shown in U.S. Pat. No. 3,293,013 incorporated herein by reference. These high speed attenuators have found utility in the production of glass fiber products having a broad range of uses. One such product, crimped glass fibers, is disclosed in U.S. patent application Ser. No. 425,974, filed Dec. 18, 1973 by Warren W. Drummond, incorporated herein by reference.
In order to form such products, a plurality of strands in parallel form are passed through the opposing flexible surfaces or belts at speeds on the order of 25 to 100 meters per second. These high speeds produce great mechanical strains on the rotating parts of the attenuator and substantially contribute to mechanical bearing failures.
Therefore, there has been a need in the utilization of such attenuators to reduce the friction caused by the high speed travel of the flexible surfaces, i.e., belts across stationary guides while the belts travel along their predetermined path.